公开(公告)号：US20230147920A1

公开(公告)日：2023-05-11

申请号：US17980033

申请日：2022-11-03

Applicant: DENSO CORPORATION

Inventor： Yuji KAJI ,  Nobuo ABE ,  Naoto HAYASHI

IPC: H01T13/39 ,  H01T13/32

CPC classification number: H01T13/39 ,  H01T13/32

Abstract: A ground electrode for a spark plug includes a ground electrode body arranged to face a center electrode of the spark plug. The ground electrode includes a discharge portion mounted on the ground electrode body to face the center electrode with a spark gap between the discharge portion and the center electrode. The discharge portion is made of a platinum-based alloy of platinum, rhodium, and nickel. A first mass percent of the rhodium contained in the platinum-based alloy of the platinum, the rhodium, and the nickel is within a first range from 2 wt % to 20 wt % inclusive. A second mass percent of the nickel contained in the platinum-based alloy of the platinum, the rhodium, and the nickel being within a second range from 2.5 wt % to 12 wt % inclusive.

公开(公告)号：US20190237943A1

公开(公告)日：2019-08-01

申请号：US16258743

申请日：2019-01-28

Applicant: DENSO CORPORATION

Inventor： Yuji KAJI

IPC: H01T13/39 ,  H01T21/00

CPC classification number: H01T13/39 ,  H01T1/00 ,  H01T21/00

Abstract: A spark plug is provided which includes a hollow cylindrical center electrode disposed inside a metal shell and a ground electrode joined to the metal shell. The ground electrode has an inner peripheral surface facing an outer peripheral surface of the center electrode. At least one of the outer periphery of the center electrode and the inner periphery of the ground electrode has formed therein at least one recess whose ends lies in a center-to-ground electrode facing region where the outer peripheral surface of the center electrode faces the inner peripheral surface of the ground electrode in a radial direction of the center electrode. This decreases voltage required by the spark plug to achieve discharge.

公开(公告)号：US20230184160A1

公开(公告)日：2023-06-15

申请号：US18105561

申请日：2023-02-03

Applicant: DENSO CORPORATION

Inventor： Yuji KAJI ,  Ryo TAMURA ,  Yasuomi IMANAKA ,  Yuuta KAWASHIMA ,  Atsushi IWAMI ,  Tatsuya OKA

IPC: F02B19/12 ,  F02P5/15 ,  F02B19/18

CPC classification number: F02B19/12 ,  F02P5/1502 ,  F02B19/18

Abstract: An ignition system includes a dividing wall which divides a combustion chamber of an engine into a main chamber and a pre-chamber and has formed therein at least one spray hole which communicates between the main chamber and the pre-chamber, and a spark plug in which voltage is applied across a spark gap between a first electrode and a second electrode to create an electrical spark to ignite fuel. The pre-chamber has the first electrode. The dividing wall or a member which electrically conducts with the dividing wall has the second electrode. The ignition system executes an after-top-dead-center ignition control mode to ignite fuel after a compression stroke top dead center. In the after-top-dead-center ignition control mode, an ignition source which is in the form of a self-growable flame kernel is provided in a spray hole-nearby region, the spray hole, or the main chamber within a crank angle of 20° after an ignition timing at which the voltage starts to be applied across the spark gap. The spray hole-nearby region is a region which is located 3 mm or less away from a spray hole center in the pre-chamber.

公开(公告)号：US20220364538A1

公开(公告)日：2022-11-17

申请号：US17874671

申请日：2022-07-27

Applicant: DENSO CORPORATION

Inventor： Yasuomi IMANAKA ,  Ryo TAMURA ,  Yuji KAJI ,  Atsushi IWAMI ,  Tatsuya OKA ,  Yuuta KAWASHIMA

IPC: F02P5/15 ,  F02P9/00

Abstract: An ignition system has an ignition plug and an ignition control unit that controls the ignition plug. When an engine is in a predetermined operating state, the ignition control unit performs ignition control after top dead center to perform ignition after the compression top dead center. The ignition system has an airflow support structure that facilitates the flow of airflow through a discharge gap at least after the compression top dead center. The ignition system is configured such that due to the airflow support structure and the timing of the ignition, airflow at a flow rate of 5 m/s or more flows through the discharge gap during a spark period after top dead center, which is the generation period of the discharge spark in the ignition control after top dead center.

公开(公告)号：US20190214791A1

公开(公告)日：2019-07-11

申请号：US16088954

申请日：2017-03-17

Applicant: DENSO CORPORATION

Inventor： Yuji KAJI ,  Koji YAMANAKA

IPC: H01T13/20

Abstract: A spark plug for an internal combustion engine that can improve bonding strength between a center electrode and a conductive glass is provided. The spark plug includes a housing, an insulator, a center electrode, a ground electrode, and a conductive glass. The center electrode has a locking portion that is locked from a base end side to a step portion formed on an inner peripheral surface of the insulator, and an electrode head that is closer to the base end side than the locking portion is. A concave portion is partially formed on the tip end surface of the electrode head. A concave contour, which is an outer peripheral contour of the concave portion when viewed in a plug axial direction, forms a closed curve which is spaced apart from a head contour, which is an outer peripheral contour of the base end surface of the electrode head, and surrounds a center axis (B) of the center electrode. The concave contour has an outward portion protruding toward the head contour and an inward portion protruding toward the center axis (B) of the center electrode.

公开(公告)号：US20190181620A1

公开(公告)日：2019-06-13

申请号：US16214505

申请日：2018-12-10

Applicant: DENSO CORPORATION

Inventor： Yuji KAJI

IPC: H01T13/16 ,  H01T13/34 ,  H01T13/38 ,  H01T13/40

Abstract: A spark plug for internal combustion engines is provided which includes a porcelain insulator which is disposed inside a housing and extends outside a front end of the porcelain insulator. An annular ground electrode is secured to a front end portion of the housing. A pocket is created between a nose of the porcelain insulator and the housing. The housing has formed therein a plurality of vent holes which are located outside the ground electrode in a radial direction of the housing and communicate between the pocket and a combustion chamber of the engine. The vent holes include a first vent hole and a second vent hole which are different in opening area from each other, thereby enhancing scavenging of the pocket to ensure the stability of operation of the spark plug.

公开(公告)号：US20230383381A1

公开(公告)日：2023-11-30

申请号：US18143654

申请日：2023-05-05

Applicant: ISHIFUKU METAL INDUSTRY CO., LTD. ,  DENSO CORPORATION

Inventor： Kenta TERAI ,  Shunsuke TAKEYA ,  Hayato YASUHARA ,  Akihiro SHIBATA ,  Ryohei AKIYOSHI ,  Yuji KAJI

IPC: C22C5/04

CPC classification number: C22C5/04

Abstract: Provided is a heat-resistant Ir alloy, which is further improved in Vickers hardness while maintaining satisfactory processability. Specifically, provided is a heat-resistant Ir alloy, including: 5 mass % to 30 mass % of Pt; 0.5 mass % to 5 mass % of Ta; and 0.003 mass % to 0.15 mass % of at least one kind selected from the group consisting of: Sc; Hf; and W, with the balance being Ir.

公开(公告)号：US20180159304A1

公开(公告)日：2018-06-07

申请号：US15828927

申请日：2017-12-01

Applicant: DENSO CORPORATION

Inventor： Masayuki TAMURA ,  Yuji KAJI ,  Yoshinori DOI ,  Shinya TANAKA ,  Atsushi YOSHIDA

IPC: H01T13/32 ,  H01T21/02 ,  B32B15/01 ,  H01T13/39

CPC classification number: H01T13/32 ,  B32B15/01 ,  H01T13/39 ,  H01T21/02

Abstract: A pipe material used as a discharge electrode of a spark plug for an internal combustion engine comprises an outer layer made of a Ni-based alloy, an inner layer made of a Pt-based alloy provided inside the outer layer, and an intermediate layer provided between the outer layer and the inner layer.